9873721728 has 384 divisors, whose sum is σ = 31913743680. Its totient is φ = 2910339072.

The previous prime is 9873721709. The next prime is 9873721757. The reversal of 9873721728 is 8271273789.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 57073450 + ... + 57073622.

Almost surely, 2^9873721728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9873721728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15956871840).

9873721728 is an abundant number, since it is smaller than the sum of its proper divisors (22040021952).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9873721728 is a wasteful number, since it uses less digits than its factorization.

9873721728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346 (or 331 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 54.

The square root of 9873721728 is about 99366.6026791698. The cubic root of 9873721728 is about 2145.3276380219.

The spelling of 9873721728 in words is "nine billion, eight hundred seventy-three million, seven hundred twenty-one thousand, seven hundred twenty-eight".